What is the most common cause of heart murmurs in children?

The most common cause of heart murmurs in children is innocent (physiologic) murmurs. These murmurs occur due to the normal flow of blood through the heart or the surrounding structures, often when the heart is functioning well and without any underlying pathology. Innocent murmurs are typically soft, short, and heard best when a child is resting or during situations of increased blood flow, such as fever or exercise.

Innocent murmurs are particularly important to identify because they signify a healthy cardiovascular system rather than a defect. Clinicians can differentiate these murmurs from pathological murmurs, which are associated with structural heart disease. Understanding that innocent murmurs are common and usually benign helps reduce anxiety for parents and reinforces the need for monitoring, rather than immediate intervention or concern.

Factors such as structural heart defects and congenital heart disease can lead to abnormal murmurs, which are often associated with more serious conditions. Rheumatic fever can also cause heart murmurs but is less common and typically linked to previous infections. In pediatric practice, distinguishing between innocent murmurs and those that indicate serious underlying heart conditions is critical for effective assessment and management.